sheet.tex

\documentclass[landscape]{article}
\usepackage[paperwidth=29.7cm,paperheight=21cm,margin=1cm]{geometry}
\usepackage{times}
\usepackage{hyperref,url}
\usepackage[T1]{fontenc}
\usepackage[scaled=0.8]{beramono}
\usepackage{rascal}
\usepackage{multicol}
\usepackage{epsfig,graphics}
\pagestyle{empty}
\setlength{\columnseprule}{.4pt}

% TODO:
% nul, min highlighting
% splicing in expression (list, set)
% for (patterns: E)
% append/fail -> fail hoger bij control-flow
% m?0 += 4;xs
% isDefined
% lexical ID indented
% [Id] "x" 

\def\mysect#1{\vspace*{-20pt}\subsection*{\textsf{#1}}\vspace*{-10pt}}

\begin{document}\sffamily
\begin{multicols}{3}

\noindent\begin{minipage}{0.7\linewidth}
\noindent\textbf{\LARGE Rascal Cheat Sheet}\\[3pt]
\noindent\url{http://www.rascal-mpl.org}\\[0pt]
\noindent\url{https://github.com/usethesource/rascal}
\end{minipage}
\begin{minipage}{0.3\linewidth}
\includegraphics[width=1\linewidth]{rascal_large_no_text.png}
%\epsfig{file=logorascal,width=\linewidth}
\end{minipage}

\vspace*{10pt}
\mysect{Modules}
\begin{rascal}
\CAT{Keyword}{module} Example

\CAT{Keyword}{import} ParseTree;         \CAT{Comment}{// import}
\CAT{Keyword}{extend} lang::std::Layout; \CAT{Comment}{// "inherit"}
\end{rascal}
\mysect{Declarations}
\begin{rascal}
\CAT{Comment}{// Algebraic data types (ADT)}
\CAT{Keyword}{data} Exp   
  = var(\CAT{Keyword}{str} x)         \CAT{Comment}{// unary constructor}
  | add(Exp l, Exp r); \CAT{Comment}{// binary constructor}

\CAT{Keyword}{data} Person        \CAT{Comment}{// keyword parameter}
  = person(\CAT{Keyword}{int} id, \CAT{Keyword}{bool} married=\CAT{Keyword}{false});

\CAT{Keyword}{alias} Age = \CAT{Keyword}{int}; \CAT{Comment}{// type alias}

\CAT{Keyword}{anno} \CAT{Keyword}{loc} Exp@location; \CAT{Comment}{// annotation}

\CAT{Keyword}{private} \CAT{Keyword}{real} PI = 3.14; \CAT{Comment}{// variables}

\CAT{Comment}{// Functions: signatures are lists of patterns}
\CAT{Comment}{// May have keyword parameters.}
\CAT{Keyword}{void} f(\CAT{Keyword}{int} x) \{{} println(x); \}{}      \CAT{Comment}{// block style}
\CAT{Keyword}{int} inc(\CAT{Keyword}{int} x) = x+1;              \CAT{Comment}{// rewrite style}
\CAT{Keyword}{int} inc0(\CAT{Keyword}{int} x) = x+1 \CAT{Keyword}{when} x == 0; \CAT{Comment}{// side condition}
\CAT{Keyword}{default} \CAT{Keyword}{int} inc0(\CAT{Keyword}{int} x) = x;       \CAT{Comment}{// otherwise}

\CAT{Comment}{// Test functions (invoke from console with :test) }
\CAT{Keyword}{test} \CAT{Keyword}{bool} add() = 1+2 == 3; 

\CAT{Comment}{// randomized test function}
\CAT{Keyword}{test} \CAT{Keyword}{bool} comm(\CAT{Keyword}{int} x, \CAT{Keyword}{int} y) = x+y == y+x; 

\CAT{Comment}{// Foreign function interface to Java}
\CAT{Comment}{@javaClass\{{}name.of.javaClass.with.Method\}{}}
\CAT{Keyword}{java} \CAT{Keyword}{int} method(); 
\CAT{Comment}{// Context-free grammars}
\CAT{Keyword}{start} \CAT{Keyword}{syntax} Prog       \CAT{Comment}{// start symbol}
  = prog: Exp* exps    \CAT{Comment}{// production}
  | stats: \{{}Stat \CAT{Constant}{";"}\}{}* \CAT{Comment}{// separated list}
  | stats: \{{}Stat \CAT{Constant}{";"}\}{}+ \CAT{Comment}{// one-or-more sep. list}
  | \CAT{Constant}{"private"}? Func;   \CAT{Comment}{// optional}

\CAT{Keyword}{syntax} Exp
  = var: Id
  | \CAT{Keyword}{left} mul: Exp l \CAT{Constant}{"*"} Exp r     \CAT{Comment}{// or right, assoc}
  | \CAT{Keyword}{left} div: Exp!div \CAT{Constant}{"/"} Exp!div \CAT{Comment}{// reject}
  \textgreater{} \CAT{Keyword}{left} add: Exp l \CAT{Constant}{"+"} Exp r     \CAT{Comment}{// "\textgreater{}" = priority}
  | \CAT{Keyword}{bracket} \CAT{Constant}{"("} Exp \CAT{Constant}{")"}; 

\CAT{Keyword}{lexical} Comment
  = \^{}\CAT{Constant}{"\#"} !{}[\CAT{Constant}{\textbackslash{}n}]* \${}; \CAT{Comment}{// begin/end markers}

\CAT{Keyword}{lexical} Id
  = ({}[\CAT{Constant}{a}-\CAT{Constant}{z}\CAT{Constant}{A}-\CAT{Constant}{Z}] !\textless{}\textless{}         \CAT{Comment}{// look behind restriction}
    {}[\CAT{Constant}{a}-\CAT{Constant}{z}\CAT{Constant}{A}-\CAT{Constant}{Z}]{}[\CAT{Constant}{a}-\CAT{Constant}{z}\CAT{Constant}{A}-\CAT{Constant}{Z}\CAT{Constant}{0}-\CAT{Constant}{9}\CAT{Constant}{\_{}}]* \CAT{Comment}{// character classes}
    !\textgreater{}\textgreater{} {}[\CAT{Constant}{a}-\CAT{Constant}{z}\CAT{Constant}{A}-\CAT{Constant}{Z}\CAT{Constant}{0}-\CAT{Constant}{9}\CAT{Constant}{\_{}}])     \CAT{Comment}{// lookahead restriction}
    \textbackslash{} Reserved;           \CAT{Comment}{// subtract keywords}

\CAT{Keyword}{layout} Layout \CAT{Comment}{// for whitespace/comments}
  = {}[\CAT{Constant}{\textbackslash{} }\CAT{Constant}{\textbackslash{}t}\CAT{Constant}{\textbackslash{}n}\CAT{Constant}{\textbackslash{}r}]*;

\CAT{Keyword}{keyword} Reserved   \CAT{Comment}{// keyword class}
  = \CAT{Constant}{"if"} | \CAT{Constant}{"else"}; \CAT{Comment}{// finite langs}
\end{rascal}
\mysect{Statements}
\begin{rascal}
\CAT{Comment}{// Standard control-flow}
\CAT{Keyword}{if} (E) S;         
\CAT{Keyword}{if} (E) S; \CAT{Keyword}{else} S;
\CAT{Keyword}{while} (E) S;
\CAT{Keyword}{do} S; \CAT{Keyword}{while}(E);
\CAT{Keyword}{continue}; \CAT{Keyword}{break}; 
\CAT{Keyword}{return}; \CAT{Keyword}{return} E;

\CAT{Comment}{// Loop over all bindings produce by patterns}
\CAT{Keyword}{for} (i \textless{}- {}[0..10]) S; \CAT{Comment}{// Loop 10 times}

\CAT{Keyword}{fail};     \CAT{Comment}{// control backtracking}
\CAT{Keyword}{append} E; \CAT{Comment}{// add to loop result list}

\CAT{Comment}{// Pattern-based switch-case}
\CAT{Keyword}{switch} (E) \{{}
  \CAT{Keyword}{case} P: S;   \CAT{Comment}{// do something}
  \CAT{Keyword}{case} P =\textgreater{} E  \CAT{Comment}{// rewrite it}
  \CAT{Keyword}{default}: S; \CAT{Comment}{// otherwise}
\}{}

\CAT{Comment}{// Traversal with visit; like switch, but matches}
\CAT{Comment}{// at arbitrary depth of value}
\CAT{Keyword}{visit} (E) \{{}
  \CAT{Keyword}{case} P: S;  \CAT{Comment}{// do something}
  \CAT{Keyword}{case} P =\textgreater{} E \CAT{Comment}{// rewrite something}
  \CAT{Keyword}{case} P =\textgreater{} E \CAT{Keyword}{when} E
\}{}
\CAT{Keyword}{insert} E; \CAT{Comment}{// rewrite subject as statement}

\CAT{Comment}{// Strategies: bottom-up, innermost, outermost,}
\CAT{Comment}{// top-down-break, bottom-up-break}
\CAT{Keyword}{top-down visit} (E) \{{}\}

\CAT{Keyword}{try} S;      \CAT{Comment}{// pattern-based try-catch}
\CAT{Keyword}{catch} P: S; \CAT{Comment}{// match to catch}
\CAT{Keyword}{finally} S;

\CAT{Keyword}{throw} E; \CAT{Comment}{// throw values}

\CAT{Comment}{// Fix-point equation solving;}
\CAT{Comment}{// iterates until all params are stable}
\CAT{Keyword}{solve} (out,ins) \{{}
  out{}[b] = ( \{{}\}{} | \CAT{Keyword}{it} + ins{}[s] | s \textless{}- succ{}[b] );
  ins{}[b] = (out{}[b] - kill{}[b]) + gen{}[b];
\}{};

x = 1;               \CAT{Comment}{// assignment   }
nums{}[0] = 1;         \CAT{Comment}{// subscript assignment}
nums{}[1,3..10] = 2;   \CAT{Comment}{// sliced (see below)}
p.age = 31;          \CAT{Comment}{// field assignment}
ast@location = l;    \CAT{Comment}{// annotation update}
\textless{}p, a\textgreater{} = \textless{}\CAT{Constant}{"ed"}, 30\textgreater{}; \CAT{Comment}{// destructuring}
 
\CAT{Comment}{// A op=E  == A = A op E}
A += E; A -= E; A *= E;
A /= E; A \&{}= E;
\end{rascal}
\mysect{Expressions}
\begin{rascal}
\CAT{Comment}{// Standard operators}
E + E; E - E; E * E; E / E; E \%{} E;
E \&{}\&{} E; E || E; E == E; E != E;
E \textgreater{} E; E \textgreater{}= E; E \textless{} E; E \textless{}= E; -E; !E;
E ? E : E; 

\CAT{Comment}{// Projections}
p.age;           \CAT{Comment}{// select field (tuple/constructor)}
p{}[age=31];       \CAT{Comment}{// update field }
ps\textless{}name,age\textgreater{};    \CAT{Comment}{// select named column(s)}
ps\textless{}1,0\textgreater{};         \CAT{Comment}{// select/swap columns by position}
graph{}[\CAT{Constant}{"from"}];   \CAT{Comment}{// image (list,str,map/rel/lrel)}
alist{}[-1];       \CAT{Comment}{// subscript (last)}
graph{}[\CAT{Constant}{"from"}, \CAT{Constant}{"label"}];
inc(2);          \CAT{Comment}{// function call}
x{}[1..10];        \CAT{Comment}{// slicing (list, string)}
x{}[0..]; x{}[..10]; \CAT{Comment}{// open slices}
x{}[..-1];         \CAT{Comment}{// negative slicing (prefix)}
x{}[0,2..10];      \CAT{Comment}{// slicing with next}
 
{}[0..10];   \CAT{Comment}{// range (incl/excl)}
{}[0,2..10]; \CAT{Comment}{// range with next }

\CAT{Comment}{// Comprehensions}
{}[ i*i | i \textless{}- {}[1..10] ];        \CAT{Comment}{// list }
\{{} \textless{}i, i*i\textgreater{} | i \textless{}- {}[1..10] \}{};   \CAT{Comment}{// set }
( i: i*i | i \textless{}- {}[1..10]);     \CAT{Comment}{// map }
( 0 | \CAT{Keyword}{it} + i | i \textless{}- {}[1..10] ); \CAT{Comment}{// reducing}

\CAT{Comment}{// Other operators}
E \CAT{Keyword}{mod} E;  \CAT{Comment}{// modulo}
E \&{} E;    \CAT{Comment}{// intersection}
E \CAT{Keyword}{join} E; \CAT{Comment}{// relation join}
E \CAT{Keyword}{o} E;    \CAT{Comment}{// compostion}

\CAT{Keyword}{all}(i \textless{}- {}[1..10], i \textgreater{} 0);      \CAT{Comment}{// big and}
\CAT{Keyword}{any}(i \textless{}- {}[1..10], i \%{} 2 == 0); \CAT{Comment}{// big or}
E ==\textgreater{} E;                       \CAT{Comment}{// implication}
E \textless{}==\textgreater{} E;                      \CAT{Comment}{// equivalence}

E \CAT{Keyword}{in} E;    \CAT{Comment}{// membership}
E \CAT{Keyword}{notin} E; \CAT{Comment}{// non-membership}
E \CAT{Keyword}{has} N; \CAT{Comment}{// has label}
E \CAT{Keyword}{is} N;  \CAT{Comment}{// is constructor}
E+; \CAT{Comment}{// transitive closure}
E*; \CAT{Comment}{// trans. refl. closure}

E{}[N=E];  \CAT{Comment}{// update field}
E{}[@N=E]; \CAT{Comment}{// update annotation}

\CAT{Comment}{// Matching and generation}
P := E;  \CAT{Comment}{// pattern match}
P !:= E; \CAT{Comment}{// anti-match}
P \textless{}- E;  \CAT{Comment}{// generator}

\CAT{Comment}{// Closures}
\CAT{Keyword}{int}(\CAT{Keyword}{int} x) \{{} \CAT{Keyword}{return} x + 1; \}{};
(\CAT{Keyword}{str} x) \{{} println(x); \}{}; \CAT{Comment}{// void}
() \{{} println(\CAT{Constant}{"y"}); \}{};    \CAT{Comment}{// nillary void }

\CAT{Comment}{// String templates}
\CAT{Constant}{"x + y = \textless{}}x + y\CAT{Constant}{\textgreater{}"}; \CAT{Comment}{// interpolation}

\CAT{Comment}{// Control-flow string interpolation (with for, if, }
\CAT{Comment}{// while, do-while). Tick (') indicates margin.}
\CAT{Comment}{// Nested templates are auto-indented.}
x = \CAT{Constant}{"\textless{}}\CAT{Keyword}{for} (i\textless{}-{}[0..10]) \{{}\CAT{Constant}{\textgreater{} 
    '  \textless{}}\CAT{Keyword}{if} (i \%{} 2 == 0) \{{}\CAT{Constant}{\textgreater{}
    '     i = \textless{}}i\CAT{Constant}{\textgreater{}
    '  \textless{}}\}{}\CAT{Constant}{\textgreater{}
    '\textless{}}\}{}\CAT{Constant}{\textgreater{}"};
\end{rascal}
\mysect{Types and values}
\begin{rascal}
\CAT{Comment}{// Atomic types}
\CAT{Keyword}{bool} x = \CAT{Keyword}{true} || \CAT{Keyword}{false};
\CAT{Keyword}{int} x = 1;
\CAT{Keyword}{real} x = 2.3E-14;
\CAT{Keyword}{rat} x = 1r2;
\CAT{Keyword}{num} x = 1 + 3.0;
\CAT{Keyword}{str} x = \CAT{Constant}{"rascal"};
\CAT{Keyword}{datetime} x = \${}1948-02-11\${};
\CAT{Keyword}{loc} x = |file:///etc/passwd|;
\CAT{Keyword}{loc} x = |file://foo|(
   10,      \CAT{Comment}{// .offset}
   5,       \CAT{Comment}{// .length}
   \textless{}1, 2\textgreater{}   \CAT{Comment}{// .begin.line, .begin.column}
   \textless{}1, 7\textgreater{}); \CAT{Comment}{// .end.line, .end.column}


\CAT{Comment}{// Tuples}
\CAT{Keyword}{tuple}{}[\CAT{Keyword}{str}, \CAT{Keyword}{int}] x = \textless{}\CAT{Constant}{"ed"}, 30\textgreater{};
\CAT{Keyword}{tuple}{}[\CAT{Keyword}{str} name, \CAT{Keyword}{int} age] x = \textless{}\CAT{Constant}{"ed"}, 30\textgreater{};

\CAT{Comment}{// Trees (all ADTs are subtype of node)}
\CAT{Keyword}{node} x = \CAT{Constant}{"person"}(\CAT{Constant}{"ed"}, 30);     \CAT{Comment}{// generic node}
Exp x = add(var(\CAT{Constant}{"x"}), var(\CAT{Constant}{"y"})); \CAT{Comment}{// ADT value}
Exp e1 = (Exp)`x * y`;           \CAT{Comment}{// concrete}
Exp e2 = (Exp)`a + (\CAT{MetaVariable}{\textless{}Exp e1\textgreater{}})`;  \CAT{Comment}{// interpolation}

\CAT{Comment}{// Collection values}
\CAT{Keyword}{list}{}[\CAT{Keyword}{int}] x = {}[1,2,3];
\CAT{Keyword}{set}{}[\CAT{Keyword}{bool}] x = \{{}\CAT{Keyword}{true},\CAT{Keyword}{false}\}{};
\CAT{Keyword}{map}{}[\CAT{Keyword}{int}, \CAT{Keyword}{bool}] x = (1: \CAT{Keyword}{true}, 2: \CAT{Keyword}{false});
\CAT{Keyword}{map}{}[\CAT{Keyword}{int} n, \CAT{Keyword}{bool} b] x = (1: \CAT{Keyword}{true}, 2: \CAT{Keyword}{false});
\CAT{Keyword}{rel}{}[\CAT{Keyword}{int}, \CAT{Keyword}{bool}] x = \{{}\textless{}1, \CAT{Keyword}{true}\textgreater{}, \textless{}2, \CAT{Keyword}{false}\textgreater{}\}{};
\CAT{Keyword}{rel}{}[\CAT{Keyword}{int} n, \CAT{Keyword}{bool} b] x = \{{}\textless{}1, \CAT{Keyword}{true}\textgreater{}, \textless{}2, \CAT{Keyword}{false}\textgreater{}\}{};
\CAT{Keyword}{lrel}{}[\CAT{Keyword}{int} n, \CAT{Keyword}{bool} b] x = {}[\textless{}1, \CAT{Keyword}{true}\textgreater{}, \textless{}1, \CAT{Keyword}{true}\textgreater{}];

\CAT{Comment}{// Functions}
\CAT{Keyword}{int}(\CAT{Keyword}{int},\CAT{Keyword}{int})f = \CAT{Keyword}{int}(\CAT{Keyword}{int} x, \CAT{Keyword}{int} y) \{{} \CAT{Keyword}{return} x+y; \}{};

\CAT{Comment}{// Misc  }
\CAT{Keyword}{value} x = anything;   \CAT{Comment}{// top type}
\CAT{Keyword}{type}{}[\CAT{Keyword}{int}] t = \#\CAT{Keyword}{int};   \CAT{Comment}{// reified types}
\CAT{Keyword}{int} size(\CAT{Keyword}{list}{}[\&{}T] l); \CAT{Comment}{// generics}
\end{rascal}
\mysect{Patterns}
\begin{rascal}
\CAT{Keyword}{int} x := 3;                           \CAT{Comment}{// typed}
x := 3;                               \CAT{Comment}{// untyped}
\textless{}\CAT{Keyword}{int} x, y\textgreater{} := \textless{}3, \CAT{Constant}{"x"}\textgreater{};               \CAT{Comment}{// tuple}
{}[1, 2, x] := {}[1, 2, 3];               \CAT{Comment}{// list}
\{{}x, 2, 3\}{} := \{{}2, 3, 1\}{};               \CAT{Comment}{// set}
{}[1, *xs, 4] := {}[1,2,3,4];             \CAT{Comment}{// splice-variable}
add(l, r) := add(var(\CAT{Constant}{"x"}), var(\CAT{Constant}{"y"})); \CAT{Comment}{// constructor}
/\CAT{Keyword}{str} x := add(var(\CAT{Constant}{"x"}), var(\CAT{Constant}{"y"}));    \CAT{Comment}{// deep}
a:add(\_{},\_{}) := x;                      \CAT{Comment}{// labeled}
Exp a:add(\_{},\_{}) := x;                  \CAT{Comment}{// typed/labeled}
/{}[a-z]/ := \CAT{Constant}{"x"};                       \CAT{Comment}{// regexp}
/.\textless{}mid:{}[a-z]\textgreater{}./ := \CAT{Constant}{"abc"};             \CAT{Comment}{// named groups }

(Exp)`\CAT{MetaVariable}{\textless{}Exp a\textgreater{}} + \CAT{MetaVariable}{\textless{}Exp b\textgreater{}}` := e2;  \CAT{Comment}{// concrete matching}
(Prog)`x, \CAT{MetaVariable}{\textless{}\{{}Exp \CAT{Constant}{","}\}{}* es\textgreater{}}` := p; \CAT{Comment}{// list matching}
\end{rascal}
\end{multicols}
\end{document}